It is frequently necessary to exchange ink fountain boxes in printing machines, for example to exchange ink of a specific color with differently colored ink. In rotary printing machines, particularly offset printing machines, it is customary to form the ink fountain boxes in such a manner that they are removable. Removal and interchange of ink fountain boxes causes problems if the ink fountain box is directly engaged against an inker roller of the printing machine inker. In such arrangements, the forward region of the inker box is open, that is, exposed to a roller so that the roller can have ink directly applied from the box, or pick up ink which flows downwardly from the box.
It is, of course, possible to install the inker box in the printing machine, when empty, and then fill ink thereinto. If the inker box is to be exchanged, however, and removed, ink may still be within the inker box and, upon removal from the printing machine, may leak off. The ink is quite viscous. In the past, this required removal of the ink from the inker box or inker fountain box before the fountain box itself could be removed from the printing machine. This is time-consuming, and frequently difficult to carry out because of the nature of the ink. Contamination, soiling and loss of ink is practically unavoidable.
It has previously been proposed to provide inker boxes with a forward cover, which is formed with an opening that can be closed by a valve closing element. This arrangement permits exchanging of inker fountain boxes with ink still therein; due the nature of the ink, however, such closure elements are difficult to handle and, if the inker box is to be used with ink of a different color, the closure valve element additionally requires cleaning.